221666223063664 has 40 divisors (see below), whose sum is σ = 431118033469568. Its totient is φ = 110410122090240.

The previous prime is 221666223063661. The next prime is 221666223063673. The reversal of 221666223063664 is 466360322666122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221666223063661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16234534 + ... + 26587450.

Almost surely, 2^{221666223063664} is an apocalyptic number.

It is an amenable number.

221666223063664 is a deficient number, since it is larger than the sum of its proper divisors (209451810405904).

221666223063664 is a wasteful number, since it uses less digits than its factorization.

221666223063664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10358033 (or 10358027 counting only the distinct ones).

The product of its (nonzero) digits is 26873856, while the sum is 55.

The spelling of 221666223063664 in words is "two hundred twenty-one trillion, six hundred sixty-six billion, two hundred twenty-three million, sixty-three thousand, six hundred sixty-four".